Alternating current power switch



Nov. 4, 1947. R. PUDELKO EI'AL 2,430,357

ALTERNATING CURRENT POWER SWITCH Filed Oct. 1, 1942 2 Sheets-Sheet lNov. 4, 1947.- R. PUDI ELKO ETAL ALTERNATING CURRENT POWER SWITCH FiledOct. 1, 1942 2 Sheets-Sheet 2 Patented Nov. 4, 1947 ALTERNATING CURRENTPOWER SWITCH Richard Pudelko, Hans Meier, and Werner Zingg, Zug,Switzerland, assignors to Landis & Gyr, A. G., Zug, Switzerland, acorporation of Switzerland Application October 1, 1942, Serial No.460,356 In Switzerland November 13, 1941 10 Claims. 1

The present invention relates to an alternating current power switch,and more particularly to automatic electric switches, remote switches orthe like for switching-on and off i1lumination-, heatand powercurrent-circuits controlled by separate apparatuses such astime-switches, electric contact instruments, temperature regulators,relays, gas-, steamand water-measuring implements for pressure,temperature, water level, or press-buttons for manual attendance, etc.

Objects and advantages of the invention will be set forth in parthereinafter and in part will be obvious herefrom, or may be learned bypractice with the invention, the same being realized and attained bymeans or the instrumentalities and combinations pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations, and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a parthereof, illustrate one embodiment of the invention, and together withthe description, serve to explain the principles of the invention.

It is the object of the present invention to provide an improved motordriven electric switch in which the contacts are relatively slowlyopened but are closed relatively swiftly.

Of the drawings:

Fig. l is a perspective View of a typical and illustrative embodiment ofthe invention, the switch being shown in open position;

Fig. 1a is a perspective view of certain parts of the switch shown inFig. 1, the members being shown in the position shortly before thecontacts are closed;

Fig. 2 is a perspective view of a modified embodiment of the invention;and

Fig. 3 is a perspective view of a further modifled embodiment of theinvention.

The invention deals with the switching-on and ofi conditions of the maincontacts of such switches as have been mentioned for higher currentintensities, in particular those above 30 amp. Whereas the switch gearsof switches of the kind mentioned have hitherto been built so thateither the switching-on and oil? movement was immediate or bothmovements were retarded, the alternating current power switch accordingto this invention is distinguished by the fact that the switch gear isdevised for performing a rapid closing movement and. a slower openingmovement of the main contacts. The closing movement can be preferablycarried out on the one 2 hand by a gearing means and a catch-workcontrolled by it, whereas on the other hand the opening movement of themain contacts isexeouted positively and immediately by the gearingmeans.

The sudden closing of the main contacts proves to be especiallyadvantageous when silver contacts are utilized for A. C. switches of thekind, inasmuch as it is performed almost free from voltaic arc andwithout sticking concomitants, thu entailing only a. slight consumptionof the contacts if by suitable dispositions in the switch gear abaille-free closing is cared for. In contrast thereto the retardedswitching-on is disadvantageous as it causes a heavy consumption of thecontacts and when incandescent lamps are switched-in the contacts arewelded due to the heavy switching-in current. Unevenness caused, forinstance, by molten drops can produce an electric arc which lasts untilthe contacts are completely closed and further contact material maythereby melt and be consumed.

There is an optimum switching-off speed. If the switching-off is tooslow or too rapid, in relation to the moment of breaking the contactswith respect to the-A. C. curve pertaining thereto, heavy sparks mayarise. With currents of 30400 amp. big electric arcs and a loudnoise'are produced. Big voltaic arcs, however, require likewise bigdimensions in the switch if flashing over is to be avoided. To a givenswitching-off speed representing the optimum just mentioned therecorresponds a minimum of sparking.

According to the invention the switching-in speed is of the order ofover 20 cm./sec., whereas the most favourable switching-off speed withan A, C. frequency of 50 cycles/sec. lies within the limits of about0.5-1 cm./sec.

Common to all the three forms of embodiment of the present invention isthe fact that they utilize an auxiliary force in the form of a Ferrarismotor I driving by way of a suitable gear a cam member 5 tensioning anddetensioning a catchwork 4, 4a, 6 and 8 which actuates the main contacts3 and I to be switched on and off. Upon tensioning the catch-work thecontacts 3 and 1 are opened by the run of the motor in positive motioncorresponding to the optimum Of the switching-oil speed, whereas thereleasing from tension of the catch-work suddenly closes the contacts.

According to the embodiment illustrated in Fig. l a plate la has securedto it a stationary touchcontact 1 arranged opposite a movablekey-contact 3 mounted on a leaf spring 6 which is attached at one end tothe plate l'a as shown by illustration, whereas its free end bears onthe edge of a strap 4 fitted with a lever arm 4a with which it isoscillatably arranged on a support set up on plate Ta. At the upper partof the lever arm la is a roller 4?) and a rest 40. The contact spring 6depresses the contact lever 4, 4a, whereby the roller ib normally bearsagainst the circumference of the catchwork controlling member designedas eccentric 5 and driven by motor I. The catch-work comprises thecontact spring 5, the contact lever 4, 4a and an angle lever B pivotallysupported by a rigid shaft; the upper arm 8a of said lever can engagewith a cranked portion the rest 40 of the contact lever 4, 4a, whereasthe lower arm 8?) projects into the path of a pin 5a fixed on aneccentric 5. The spring 80 tends constantly to press the angle lever 8against the lever arm 4a.

The controlling eccentric 5 is keyed on shaft M on which an arm 11 isrigidly secured. Further, for forming a slipping coupling on the shaftI4 a gear wheel 9 is arranged thereon frictiontight by the slipping disk9a. The wheel 9 engages a piniOn 9b on the axis of the driving disk I aof the motor I. On plate l8 a pin I9 is provided projecting into thepath of the arm I? rigidly mounted on the shaft, Finally, on the shafthi there is a storage spring II] the one end of which being attached tothe shaft, th other end fixed in the plate I8.

The action of this device is as follows:

In Fig. 1 the parts are represented in the position corresponding to theopen contacts 3 and 1. If the switch is to be switched-on, i. e., thecontacts 3 and I closed, the motor current-circuit is switched-in byhand or some suitable controlling apparatus; the motor is started andits driving disk Ia revolved in the direction indicated by the arrow P.Thereby the shaft l4 rotates so far in the direction of the arrow P1through pinion 9b and friction-wheel 9 until the arm I! of the shaft Mhas almost completed one revolution. By this the storage spring H] hasbeen tensioned.

During this revolution the eccentric 5 has revolved in the samedirection as the shaft l4, whereby the front face Of the eccentric 5which touches the roller 4b of lever 4a leaves the roller 41) and thepin 5a of the eccentric 5 comes into the vicinity of the lower arm 81)of the angle lever B. The

arm ll of the shaft now stands close to the position in which thestorage spring I8 is tensioned. Upon further revolving the pin 5a of theeccentric 5 presses against the lower arm of the angle lever 8, rocks itcontrary to the action of the spring So, so that it drops with its noseout of the rest 40, whereby the contact lever 4, 4a falls due to itsgravity and the pressure of the contact spring 6. This causes the suddenclosing of the key-contacts 3 and 7.

The switched-in position of the contacts 3 and I is maintained as longas the motor is under voltage, i. e., as long as the voltage does notdrop below a prescribed minimum measure. Should the motor voltage sinkbelow the respective minimum measure or fail entirely, then the torqueof the storage spring 10 outweights that of the motor so that now theshaft l4 upon releasing of the spring i8 is moved backwards in thedirection of arrow P2. The contact lever 4, 4a resting in the closedposition of the contacts with the roller 42) on the eccentric 5 is nowraised with the rotation of the shaft E 4 till the nose 8a of the anglelever 8 engages the rest 4:: of the lever do, during which movement thecontacts 3 and I are opened and the catch-work simultaneously tensionedafresh. As the motor disk must be carried along with the comparativelybig inertia effect and, in addition the other conditions ma be alsoselected at will, the desired slow opening movement of the contactsensues. With the backward motion of the shaft M causing the opening ofthe contacts the flying mass (driving disk la, wheel 9, lever ll,eccentric 5) is braked by the impinging of the lever I! on pin l9 (Fig.l) by means of the friction coupling 9, So, so that injurious jerkingsheets are avoided.

In the example shown in Fig. 2 the switch is connected in alternateswitching with a controlling apparatus 20. In addition, the drive of thecontrolling member 5 for the catch-work is ac complished by way of anintermediate device which, driven by the motor l, prevents the contactsfrom sticking in an intermediate position between the switched-on andoff position for any reason, such as voltage failure in the network andconsequently giving rise to sparking and other injuries to the switch.

In this form of embodiment the main contacts 3 and l are again arrangedand designed in the manner already described with reference to the firstdesign. The contact lever 4, 4a cooperates here with an arm 5 ascontrolling member attached on the shaft 14 and provided with tworollers 5a, 5b. Further, the shaft I l carries the wheel l3a looselymounted thereon which is part of a gearing set 13 leading to the drivingdisk m of the motor l. At the other end of the shaft M a curved disk inthe shape of two superimposed hearts I! is fixed thereon with the rests92c and 12d against which two pivotally supported rollers lie, it?) ontwo lever arms 12a, lZb bear by means of the spring 2! connecting bothlevers l2a, 2b. The curved disk 1 i has attached to it a pin which cancooperate with a pin 23 on the loose wheel Ba in the way describedfurther below.

lvioreovcr, on shaft (4 a contact cam 24 is arranged adapted to engagethe contact spring 2%; for the double contact 25, 25. The contactsprings 24a, 25a and 25a are, as diagrammatically represented, connectedto the outside mains through the control switch 23 and the motor 5.

The action is now as follows:

Fig. 2 illustrates the position for initiating the switching-01f orswitching-on performance of the main contacts 3 and I. When on thecontrol apparatus 22 th contact is shifted to a, voltage is passed viacontact 25 to the motor which drives through the gearing [3 the wheell3a in the direction indicated by the arrow. The wheel l3a pushes withits pin 23 against the pin 22 of the superimposed hearts i I, revolvingthis and hence the shaft i l in the direction of the arrow P3, wherebythe rollers Ila, lib run up the heart curves and the spring 2! becomestensioned. During the first turn of the roller 5b of the arm 5 raisesthe lever 4a according to the vel city predetermined by the gear,whereby the contacts 3 and I are opened comparatively slowly and evenly.Upon further movement of the heart I l that is to say after its top(upper point) has reached the roller Hit, it snaps further with quickmotion due to detensioning or the sprin 2! until the roller i to fallsinto the rest l 20 and the roller 5 it) into the rest lZd. Upon thisfurther rotation of 99 the lever 4 has fallen from the roller Eb ontoroller 5a (of. the dotted position of the arm 5 and of the contact lever4, 4a), Up to now the shaft M has turned through The contact spring 24ahas hereby arrived on the lowest point of the cam 24 and broken thecontact 25 and consequently the motor current-circuit. Contrary to thedesign shown in Fig. 1 in which the motor I is alive even in theofi-position of the switch, the motor is disconnected in this caseimmediately after opening the contacts 3 and I, i. e., after theswitching performance.

When the switch has now to be switched-on, i. e., the contacts 3 and 1closed, the contact is set to b in the control apparatus 2%. As in thisposition of the shaft or the cam 24 the contact spring 24a still closesthe contact 26, the motor current-circuit is again alive; the motorstarts and turns the double heart H further in the aforementioned mannerin the direction of the arrow P3, whereby the contact lever 4,flea-shown in the dotted positioin drops from the rolleria of thesteering member 5 and thus the contacts 3 and "l are instantaneouslyclosed. The double heart II is now at the end of the third 90-turn; thecam 24 then cuts out the contact 26 through the contact spring 24a andwith it the motor current-circuit. The accomplishment of the com pleterevolution of the shaft and of the controlling member 5, respectively,into the position as drawn out in solid lines in Fig. 2 is brought aboutby the device I i.

The use of the intermediate device ll for con trolling the shaft i4makes it possible that, when in an intermediate position of the con actsthe driving motor goes dead for any reason, the device is not setquiescent in this position but resumes one corresponding to theswitched-on or On condition. If, for instance, starting from theposition as shown in Fig. 2, the superimposed heart H has turned through50", the contacts 3 and I are already slightly opened. Should now themo" tor I not be alive, the steering member 5 guiding the contact lever4, 4a with the contact 3 does not remain in this position, in which apermanent spark might occur between. the contacts 3 and "I, as thespring 2! by means of the rollers lo, I lb thrusts the double-heart Hback again into the illustrated initial position, i. e., into theswitched-on position. Similarly, the controlling device ll functions inother intermediate positions, in which the motor, unintentionally,stands still.

With the described loose connection between the pinion He and thedouble-heart l I, the latter r and consequently the shaft I4 performstwo slow movements in the course of one revolution corresponding to itscurve guidance (running up of the curves on the rollers Ila, Nb) and twoquick movements (running off of the curves on the rollers).

In order to ensure an even running off of the shaft l4 and therewith ofthe controlling member 5, the pinion lea may either be rigidly mountedon the shaft M or, e. g., the pins 22 and 23 screwed together. In doingso, a retarded, i. e., even revolution of the shaft I4 is obtained,whereby the gearing set IS with the driving disk la of the motor 1serves as a retardation medium or check.

Fig. 3 illustrates an actual retardation device by mechanical backcoupling of the controlling member 5 with the motor l. Here, too, wehave a power switch alternately connected to a control apparatus 25!such as shown in Fig. 2. In this embodiment, too, the motor runsinvariably in the same direction as with the switch according to Fig. 2.It is similar also with respect to the controlling of shaft l4 by asuperimposed heart similarly equipped and designed as the switch on Fig.2. With this retardation deviceasin the embodiment in Fig. 2 withretardati0na lever 5 with a roller 5a suffices as controlling member forthe catch-work. Through the retardation device, more fully describedbelow, the run of the controlling member 5 is governed in such a waythat a second roller, as, in the example according to Fig. 2 withoutretardation, is dispensed with.

- The retardation device according to Fig, 3 comprises in addition tothe loosely mounted wheel I3a of the normal gear drive between motor I.and shaft I4 another wheel lSa riding on shaft M. This wheel, however isrigidly supported thereon and associated with a set of wheels lEc, idand and IE6 arranged on the shaft l3b. The wheel [to is keyed on theshaft l3b, whereas the rigidly connected together wheels Hid, lBe areloosely mounted thereon. The wheel I has a pawl 21 which engages theratchet wheel I611.

The action of the device in Fig. 3 is substantially the same as that ofthe retardation device in Fig. 2. Upon rotation of the double-heartcurve H in the direction of the arrow P3 the two rapid movements of theshaft-when the rollers run off On the double-heart curves-are checked bythe gear Ida-[6c as the wheels l6a, We and Mid and consequently theshaft is coupled throughthe pawl 21 with the gear set I3 of the motor Iwhereby the desired check or drag, i. e., the smooth running of theshaft I4 is attained.

In the illustrated forms of embodiment only one contact pair 3 and Iis'shoWn. Obviously, the present invention may likewise be applied inconnection with multipolar switches.

Each single phase is preferably provided with a separate spark chambercovered to the top. The covering, however, must not be a through one,but must be carried out phase for phase so that possible metalprecipitations derived from the contacts cannot constitute conductiveconnections between the single phases.

Furthermore, there is a possibility offered within the scope of theinvention of providing the switch so that it is-upon closing the motorcircuitcapable to switch-in, sever or commutate.

While we have described certain specific embodiments of our invention itis to be understood that the details of construction may be changed bythose skilled in the art within the purview of the appended claims.

We claim:

1. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, a shaft adapted to be drvien thereby, a resilientelement connected to one contact and adapted to be tensioned while thecontacts are moved. slowly apart, control means disposed between theshaft and resilient element and adapted to be operated by the shaft fora control action to tension the resilient element and hold it tensionedand the contacts separated for a predetermined period and adapted to beoperated by the shaft for a second control action to release saidelement and allow the contacts to be brought together thereby, andenergy storing means rendered operative for action when the motor is energized for subsequently driving the shaft to effect the first-namedcontrol action when the motor is deenergized.

2. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, a shaft adapted to be driven thereby, a resilientelement connected to one contact and ad pte to be tensioned while thecontacts are moved slowly apart, cam operated control means adapted tobe actuated by the shaft for a control action to tension said elementand hold the same tensioned and the contacts separated for apredetermined period and adapted to be actuated by the shaft for asecond control action to release said element and allow the contacts tobe brought together thereby, and a motor spring, tensioned for actionwhen the shaft is driven by the motor for subsequently driving the shaftto effect the first-named control action when the motor is deenergized.

3. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, a shaft adapted to be driven thereby, a leafspring element connected to one contact and adapted to be tensionedwhile the contacts are moved slowly apart, control means adapted to beoperated b the shaft for a control action to tension the leaf springelement and hold it tensioned and the contacts open for a predeterminedperiod and adapted to be operated by the shaft for a second controlaction to release said element and allow the contacts to be broughttogether thereby, and energy storing means rendered operative for actionwhen the motor is energized for subsequently driving the shaft to effectthe first-named control action when the motor is deenergized.

4. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, a shaft adapted to be driven thereby, a leafspring element connected to one contact and adapted to be tensionedwhile slowly moving the said contact away from the other contact, camoperated control means adapted to be actuated by the shaft for a controlaction to tension said leaf spring element and hold the same tensionedand the contacts separated for a predetermined period and adapted to beactuated by the shaft for a second control action to release saidelement and allow the contacts to be brought together thereby, and amotor spring energized by the shaft in its aforesaid operation by themotor for subsequently driving the shaft to effect the first-namedcontrol action when the motor is deenergized.

5. A motor actuated electric switch comprising, in combination, a pairof contacts, a tension de vice for moving one contact toward the othercontact, a motor, control means disposed between the motor and tensiondevice operative for a control action to simultaneously tension saidtension device and move the contacts slowly apart and hold the same frommovement and operative for a second control action to release saidtension device for movement and action to bring the contacts rapidilytogether, and energy storing means coacting with and governed by andgoverning the motor and acting on said control means for effecting saidfirst-named control action to separate the contacts when the motor isdeenergized,

6. A motor actuated electric switch comprising, in combination, a pairof contacts, a tension device for moving one contact toward the othercontact, a motor, control means arranged between the motor and thetension device and operative for a control action to simultaneouslytension the tension device and slowly move the contacts apart and holdthe same from movement and operative for a second control action torelease the tension device for action and allow 8 the contacts to bebrought together thereby, and means controlled by the motor andgoverning said control means for effecting said secondnamed controlaction,

7. A motor actuated electric switch compris ing, in combination, a pairof contacts, an electric motor, and control means between the electricmotor and contacts for moving the contacts apart relatively slowly andfor movin the contacts together relatively swiftly comprisin springmeans carrying one of said contacts and normally urging said contactstogether, a lever for tensioning and releasing said spring means fromtension, cam means engaging said lever for tensioning the spring meansand moving said contacts apart, catch means engageable with said leverto hold the contacts in spaced apart relationship and operable by thecam means to release said lever to allow the spring means to close thecontacts when the motor is energized, and a spring operatively connectedwith and tensioned when the motor is energized and acting, when themotor is deenergized, to actuate said cam means and the lever engagedthereby, for tensioning said spring means and thereby separating thecontacts,

8. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, and driving means between the motor and contactsfor moving the contacts apart relatively slowly and moving the contactstogether relatively swiftly by power from the motor, said meanscomprising spring means carrying one of said contacts and urging saidcontacts together, cam means for moving said contacts apart and tensioning said spring means, an energy storing spring operativelyconnected with and tensioned when the motor is energized and acting,when the motor is deenergized, to actuate said cam means for tensioningsaid spring means and thereby separating the contacts, catch means forholdin said spring means inactive but in tensioned position andmaintaining said contacts in spaced apart relationship, and meansincluding said cam means actuated by said motor when the motor isenergized for tensioning said energ storing spring and tripping saidcatch means for releasing said spring means from tension and therebyclosing the contacts.

9. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, spring means carrying one of said contacts andnormally urging said contacts together, cam means for tensioning saidspring means and movin said contacts apart, latching means formaintaining said spring means under tension and said contacts in spacedapart relation, control means including said cam means actuated by themotor when the motor is energized for tripping said latching meanswhereby the spring means are released from tension and the contactsmoved together thereby, and other spring means tensioned when saidcontrol means are driven by the energized motor and released fromtension to return said cam means to an initial position when the motoris deenergized.

10. A motor actuated electric switch comprising, in combination, a pairof contacts, a motor, spring means urging said contacts together, a camfor tensioning said spring means and moving said contacts apart and forreleasing said spring means from tension to allow said contacts to bemoved together thereby, and means for controlling said cam means fromthe motor to bring the contacts together when the motor is energized andthen stall the motor and tension 9 10 said spring means and therebyseparate the con- UNITED STATES PATENTS tacts when the motor isdeenergized.

R H PUDELKO Number Name Date HANS MEIER, 47,071 Besag July 20, 1915WERNER ZINGG, 5 ,1 ,41 Skinner Aug. 11, 1914 1,272,445 Holliday July 16,1918 REFERENCES CITED 2,083,425 Beusch June 8, 1937 The followingreferences are of record in the file of this patent:

